1. Field of the Invention
The present invention relates to a cogeneration system including a heat pump type air conditioner, and, more particularly, to a cogeneration system in which waste heat of a drive source adapted to drive a generator is used to heat indoor air, and thus, to maximize the heating efficiency of a heat pump type air conditioner included in the cogeneration system.
2. Description of the Related Art
In general, cogeneration systems include an engine, a generator to generate electricity, using a rotating force outputted from the engine, a heat pump type air conditioner, which is operated with the electricity generated from the generator, and is switched between cooling and heating modes, a thermal storage tank to heat water for supply of hot water, and a heat supply line to supply heat of exhaust gas discharged from the engine and heat of cooling water used to cool the engine.
The generator has a rotor coupled to an output shaft of the engine.
The heat pump type air conditioner includes a compressor, a 4-way valve, an indoor heat exchanger, an expansion device, and an outdoor heat exchanger, which are connected in series by a refrigerant conduit.
Hereinafter, operation of a conventional cogeneration system, which has the above-mentioned configuration, will be described.
When the engine drives, the rotor of the generator is rotated by the output shaft of the engine, so that the generator generates electricity. The generated electricity is used to operate the heat pump type air conditioner or various electrical devices such as electric lamps.
Meanwhile, waste heat generated from the engine is supplied to the thermal storage tank via the heat supply line so that the supplied waste heat is used as a heat source to heat water for supply of hot water.
When the heat pump type air conditioner operates in a heating mode, the compressor is driven to compress a refrigerant. At this time, the 4-way valve establishes a flow path to allow the compressed refrigerant to be circulated through the indoor heat exchanger, expansion device, outdoor heat exchanger, and compressor, in this order. The indoor heat exchanger functions as a condenser to heat indoor air.
On the other hand, when the heat pump type air conditioner operates in a cooling mode, the compressor is driven to compress a refrigerant. At this time, the 4-way valve establishes a flow path to allow the compressed refrigerant to be circulated through the outdoor heat exchanger, expansion device, indoor heat exchanger, and compressor, in this order. The indoor heat exchanger functions as an evaporator to cool indoor air.
However, the above-mentioned conventional cogeneration system has a problem of low system efficiency because the waste heat of the engine is used only to heat water for supply of hot water.